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-rw-r--r--arch/i386/Kconfig4
-rw-r--r--arch/i386/kernel/semaphore.c162
-rw-r--r--arch/um/Kconfig_i3864
-rw-r--r--arch/um/Kconfig_x86_644
-rw-r--r--arch/um/sys-x86_64/Makefile5
-rw-r--r--arch/x86_64/Kconfig4
-rw-r--r--arch/x86_64/kernel/Makefile2
-rw-r--r--arch/x86_64/kernel/semaphore.c180
8 files changed, 19 insertions, 346 deletions
diff --git a/arch/i386/Kconfig b/arch/i386/Kconfig
index dcb0ad0..3b3b017 100644
--- a/arch/i386/Kconfig
+++ b/arch/i386/Kconfig
@@ -14,6 +14,10 @@ config X86
486, 586, Pentiums, and various instruction-set-compatible chips by
AMD, Cyrix, and others.
+config SEMAPHORE_SLEEPERS
+ bool
+ default y
+
config MMU
bool
default y
diff --git a/arch/i386/kernel/semaphore.c b/arch/i386/kernel/semaphore.c
index 469f496..7455ab6 100644
--- a/arch/i386/kernel/semaphore.c
+++ b/arch/i386/kernel/semaphore.c
@@ -13,171 +13,9 @@
* rw semaphores implemented November 1999 by Benjamin LaHaise <bcrl@kvack.org>
*/
#include <linux/config.h>
-#include <linux/sched.h>
-#include <linux/err.h>
-#include <linux/init.h>
#include <asm/semaphore.h>
/*
- * Semaphores are implemented using a two-way counter:
- * The "count" variable is decremented for each process
- * that tries to acquire the semaphore, while the "sleeping"
- * variable is a count of such acquires.
- *
- * Notably, the inline "up()" and "down()" functions can
- * efficiently test if they need to do any extra work (up
- * needs to do something only if count was negative before
- * the increment operation.
- *
- * "sleeping" and the contention routine ordering is protected
- * by the spinlock in the semaphore's waitqueue head.
- *
- * Note that these functions are only called when there is
- * contention on the lock, and as such all this is the
- * "non-critical" part of the whole semaphore business. The
- * critical part is the inline stuff in <asm/semaphore.h>
- * where we want to avoid any extra jumps and calls.
- */
-
-/*
- * Logic:
- * - only on a boundary condition do we need to care. When we go
- * from a negative count to a non-negative, we wake people up.
- * - when we go from a non-negative count to a negative do we
- * (a) synchronize with the "sleeper" count and (b) make sure
- * that we're on the wakeup list before we synchronize so that
- * we cannot lose wakeup events.
- */
-
-static fastcall void __attribute_used__ __up(struct semaphore *sem)
-{
- wake_up(&sem->wait);
-}
-
-static fastcall void __attribute_used__ __sched __down(struct semaphore * sem)
-{
- struct task_struct *tsk = current;
- DECLARE_WAITQUEUE(wait, tsk);
- unsigned long flags;
-
- tsk->state = TASK_UNINTERRUPTIBLE;
- spin_lock_irqsave(&sem->wait.lock, flags);
- add_wait_queue_exclusive_locked(&sem->wait, &wait);
-
- sem->sleepers++;
- for (;;) {
- int sleepers = sem->sleepers;
-
- /*
- * Add "everybody else" into it. They aren't
- * playing, because we own the spinlock in
- * the wait_queue_head.
- */
- if (!atomic_add_negative(sleepers - 1, &sem->count)) {
- sem->sleepers = 0;
- break;
- }
- sem->sleepers = 1; /* us - see -1 above */
- spin_unlock_irqrestore(&sem->wait.lock, flags);
-
- schedule();
-
- spin_lock_irqsave(&sem->wait.lock, flags);
- tsk->state = TASK_UNINTERRUPTIBLE;
- }
- remove_wait_queue_locked(&sem->wait, &wait);
- wake_up_locked(&sem->wait);
- spin_unlock_irqrestore(&sem->wait.lock, flags);
- tsk->state = TASK_RUNNING;
-}
-
-static fastcall int __attribute_used__ __sched __down_interruptible(struct semaphore * sem)
-{
- int retval = 0;
- struct task_struct *tsk = current;
- DECLARE_WAITQUEUE(wait, tsk);
- unsigned long flags;
-
- tsk->state = TASK_INTERRUPTIBLE;
- spin_lock_irqsave(&sem->wait.lock, flags);
- add_wait_queue_exclusive_locked(&sem->wait, &wait);
-
- sem->sleepers++;
- for (;;) {
- int sleepers = sem->sleepers;
-
- /*
- * With signals pending, this turns into
- * the trylock failure case - we won't be
- * sleeping, and we* can't get the lock as
- * it has contention. Just correct the count
- * and exit.
- */
- if (signal_pending(current)) {
- retval = -EINTR;
- sem->sleepers = 0;
- atomic_add(sleepers, &sem->count);
- break;
- }
-
- /*
- * Add "everybody else" into it. They aren't
- * playing, because we own the spinlock in
- * wait_queue_head. The "-1" is because we're
- * still hoping to get the semaphore.
- */
- if (!atomic_add_negative(sleepers - 1, &sem->count)) {
- sem->sleepers = 0;
- break;
- }
- sem->sleepers = 1; /* us - see -1 above */
- spin_unlock_irqrestore(&sem->wait.lock, flags);
-
- schedule();
-
- spin_lock_irqsave(&sem->wait.lock, flags);
- tsk->state = TASK_INTERRUPTIBLE;
- }
- remove_wait_queue_locked(&sem->wait, &wait);
- wake_up_locked(&sem->wait);
- spin_unlock_irqrestore(&sem->wait.lock, flags);
-
- tsk->state = TASK_RUNNING;
- return retval;
-}
-
-/*
- * Trylock failed - make sure we correct for
- * having decremented the count.
- *
- * We could have done the trylock with a
- * single "cmpxchg" without failure cases,
- * but then it wouldn't work on a 386.
- */
-static fastcall int __attribute_used__ __down_trylock(struct semaphore * sem)
-{
- int sleepers;
- unsigned long flags;
-
- spin_lock_irqsave(&sem->wait.lock, flags);
- sleepers = sem->sleepers + 1;
- sem->sleepers = 0;
-
- /*
- * Add "everybody else" and us into it. They aren't
- * playing, because we own the spinlock in the
- * wait_queue_head.
- */
- if (!atomic_add_negative(sleepers, &sem->count)) {
- wake_up_locked(&sem->wait);
- }
-
- spin_unlock_irqrestore(&sem->wait.lock, flags);
- return 1;
-}
-
-
-/*
* The semaphore operations have a special calling sequence that
* allow us to do a simpler in-line version of them. These routines
* need to convert that sequence back into the C sequence when
diff --git a/arch/um/Kconfig_i386 b/arch/um/Kconfig_i386
index 27c18a8..8ad156a 100644
--- a/arch/um/Kconfig_i386
+++ b/arch/um/Kconfig_i386
@@ -6,6 +6,10 @@ config 64BIT
bool
default n
+config SEMAPHORE_SLEEPERS
+ bool
+ default y
+
config TOP_ADDR
hex
default 0xc0000000 if !HOST_2G_2G
diff --git a/arch/um/Kconfig_x86_64 b/arch/um/Kconfig_x86_64
index 735a047..6e5357c 100644
--- a/arch/um/Kconfig_x86_64
+++ b/arch/um/Kconfig_x86_64
@@ -6,6 +6,10 @@ config 64BIT
bool
default y
+config SEMAPHORE_SLEEPERS
+ bool
+ default y
+
config TOP_ADDR
hex
default 0x80000000
diff --git a/arch/um/sys-x86_64/Makefile b/arch/um/sys-x86_64/Makefile
index 7488206..736d3ed 100644
--- a/arch/um/sys-x86_64/Makefile
+++ b/arch/um/sys-x86_64/Makefile
@@ -6,7 +6,7 @@
#XXX: why into lib-y?
lib-y = bitops.o bugs.o csum-partial.o delay.o fault.o mem.o memcpy.o \
- ptrace.o ptrace_user.o semaphore.o sigcontext.o signal.o stub.o \
+ ptrace.o ptrace_user.o sigcontext.o signal.o stub.o \
stub_segv.o syscalls.o syscall_table.o sysrq.o thunk.o
obj-y := ksyms.o
@@ -15,7 +15,7 @@ obj-$(CONFIG_MODULES) += module.o um_module.o
USER_OBJS := ptrace_user.o sigcontext.o
SYMLINKS = bitops.c csum-copy.S csum-partial.c csum-wrappers.c memcpy.S \
- semaphore.c thunk.S module.c
+ thunk.S module.c
include arch/um/scripts/Makefile.rules
@@ -24,7 +24,6 @@ csum-copy.S-dir = lib
csum-partial.c-dir = lib
csum-wrappers.c-dir = lib
memcpy.S-dir = lib
-semaphore.c-dir = kernel
thunk.S-dir = lib
module.c-dir = kernel
diff --git a/arch/x86_64/Kconfig b/arch/x86_64/Kconfig
index 660a03a..75e52c5 100644
--- a/arch/x86_64/Kconfig
+++ b/arch/x86_64/Kconfig
@@ -24,6 +24,10 @@ config X86
bool
default y
+config SEMAPHORE_SLEEPERS
+ bool
+ default y
+
config MMU
bool
default y
diff --git a/arch/x86_64/kernel/Makefile b/arch/x86_64/kernel/Makefile
index 48f9e2c..427501a 100644
--- a/arch/x86_64/kernel/Makefile
+++ b/arch/x86_64/kernel/Makefile
@@ -4,7 +4,7 @@
extra-y := head.o head64.o init_task.o vmlinux.lds
EXTRA_AFLAGS := -traditional
-obj-y := process.o semaphore.o signal.o entry.o traps.o irq.o \
+obj-y := process.o signal.o entry.o traps.o irq.o \
ptrace.o time.o ioport.o ldt.o setup.o i8259.o sys_x86_64.o \
x8664_ksyms.o i387.o syscall.o vsyscall.o \
setup64.o bootflag.o e820.o reboot.o quirks.o
diff --git a/arch/x86_64/kernel/semaphore.c b/arch/x86_64/kernel/semaphore.c
deleted file mode 100644
index 48f7c18..0000000
--- a/arch/x86_64/kernel/semaphore.c
+++ /dev/null
@@ -1,180 +0,0 @@
-/*
- * x86_64 semaphore implementation.
- *
- * (C) Copyright 1999 Linus Torvalds
- *
- * Portions Copyright 1999 Red Hat, Inc.
- *
- * This program is free software; you can redistribute it and/or
- * modify it under the terms of the GNU General Public License
- * as published by the Free Software Foundation; either version
- * 2 of the License, or (at your option) any later version.
- *
- * rw semaphores implemented November 1999 by Benjamin LaHaise <bcrl@kvack.org>
- */
-#include <linux/config.h>
-#include <linux/sched.h>
-#include <linux/init.h>
-#include <asm/errno.h>
-
-#include <asm/semaphore.h>
-
-/*
- * Semaphores are implemented using a two-way counter:
- * The "count" variable is decremented for each process
- * that tries to acquire the semaphore, while the "sleeping"
- * variable is a count of such acquires.
- *
- * Notably, the inline "up()" and "down()" functions can
- * efficiently test if they need to do any extra work (up
- * needs to do something only if count was negative before
- * the increment operation.
- *
- * "sleeping" and the contention routine ordering is protected
- * by the spinlock in the semaphore's waitqueue head.
- *
- * Note that these functions are only called when there is
- * contention on the lock, and as such all this is the
- * "non-critical" part of the whole semaphore business. The
- * critical part is the inline stuff in <asm/semaphore.h>
- * where we want to avoid any extra jumps and calls.
- */
-
-/*
- * Logic:
- * - only on a boundary condition do we need to care. When we go
- * from a negative count to a non-negative, we wake people up.
- * - when we go from a non-negative count to a negative do we
- * (a) synchronize with the "sleeper" count and (b) make sure
- * that we're on the wakeup list before we synchronize so that
- * we cannot lose wakeup events.
- */
-
-void __up(struct semaphore *sem)
-{
- wake_up(&sem->wait);
-}
-
-void __sched __down(struct semaphore * sem)
-{
- struct task_struct *tsk = current;
- DECLARE_WAITQUEUE(wait, tsk);
- unsigned long flags;
-
- tsk->state = TASK_UNINTERRUPTIBLE;
- spin_lock_irqsave(&sem->wait.lock, flags);
- add_wait_queue_exclusive_locked(&sem->wait, &wait);
-
- sem->sleepers++;
- for (;;) {
- int sleepers = sem->sleepers;
-
- /*
- * Add "everybody else" into it. They aren't
- * playing, because we own the spinlock in
- * the wait_queue_head.
- */
- if (!atomic_add_negative(sleepers - 1, &sem->count)) {
- sem->sleepers = 0;
- break;
- }
- sem->sleepers = 1; /* us - see -1 above */
- spin_unlock_irqrestore(&sem->wait.lock, flags);
-
- schedule();
-
- spin_lock_irqsave(&sem->wait.lock, flags);
- tsk->state = TASK_UNINTERRUPTIBLE;
- }
- remove_wait_queue_locked(&sem->wait, &wait);
- wake_up_locked(&sem->wait);
- spin_unlock_irqrestore(&sem->wait.lock, flags);
- tsk->state = TASK_RUNNING;
-}
-
-int __sched __down_interruptible(struct semaphore * sem)
-{
- int retval = 0;
- struct task_struct *tsk = current;
- DECLARE_WAITQUEUE(wait, tsk);
- unsigned long flags;
-
- tsk->state = TASK_INTERRUPTIBLE;
- spin_lock_irqsave(&sem->wait.lock, flags);
- add_wait_queue_exclusive_locked(&sem->wait, &wait);
-
- sem->sleepers++;
- for (;;) {
- int sleepers = sem->sleepers;
-
- /*
- * With signals pending, this turns into
- * the trylock failure case - we won't be
- * sleeping, and we* can't get the lock as
- * it has contention. Just correct the count
- * and exit.
- */
- if (signal_pending(current)) {
- retval = -EINTR;
- sem->sleepers = 0;
- atomic_add(sleepers, &sem->count);
- break;
- }
-
- /*
- * Add "everybody else" into it. They aren't
- * playing, because we own the spinlock in
- * wait_queue_head. The "-1" is because we're
- * still hoping to get the semaphore.
- */
- if (!atomic_add_negative(sleepers - 1, &sem->count)) {
- sem->sleepers = 0;
- break;
- }
- sem->sleepers = 1; /* us - see -1 above */
- spin_unlock_irqrestore(&sem->wait.lock, flags);
-
- schedule();
-
- spin_lock_irqsave(&sem->wait.lock, flags);
- tsk->state = TASK_INTERRUPTIBLE;
- }
- remove_wait_queue_locked(&sem->wait, &wait);
- wake_up_locked(&sem->wait);
- spin_unlock_irqrestore(&sem->wait.lock, flags);
-
- tsk->state = TASK_RUNNING;
- return retval;
-}
-
-/*
- * Trylock failed - make sure we correct for
- * having decremented the count.
- *
- * We could have done the trylock with a
- * single "cmpxchg" without failure cases,
- * but then it wouldn't work on a 386.
- */
-int __down_trylock(struct semaphore * sem)
-{
- int sleepers;
- unsigned long flags;
-
- spin_lock_irqsave(&sem->wait.lock, flags);
- sleepers = sem->sleepers + 1;
- sem->sleepers = 0;
-
- /*
- * Add "everybody else" and us into it. They aren't
- * playing, because we own the spinlock in the
- * wait_queue_head.
- */
- if (!atomic_add_negative(sleepers, &sem->count)) {
- wake_up_locked(&sem->wait);
- }
-
- spin_unlock_irqrestore(&sem->wait.lock, flags);
- return 1;
-}
-
-
generated by cgit v1.1 at 2024-12-27 11:11:24 +0000